Correct
三十年河东，三十年河西
/ sān shí nián hédōng, sān shí nián héxī /
Strokes
Definition
the river flows thirty years to the East, thirty years to the West (proverb)/change is the only constant
Example
Definition
for thirty years, people east of the river prosper, then for another thirty years those on the west prosper—life full of ups and downs; chequered career; vicissitudes of life